The chapter
Simply This is the chapter the book turns on. Halfway through it Peter says who he thinks Jesus is, and immediately afterward Jesus starts teaching something the disciples had not heard before: that he is going to be rejected and killed.
Context Everything before that point is about not seeing. The disciples cannot work out where bread would come from after watching him feed five thousand, he asks them whether they have eyes and do not see, and a blind man at Bethsaida is healed in two stages, seeing men like walking trees before he sees clearly. The confession follows in the next paragraph, and what follows the confession is a rebuke.
Verses 1-21
Simply A second crowd, four thousand this time, has been with him three days with nothing to eat, and seven loaves feed them with seven baskets left. In the boat afterward the disciples worry that they brought only one loaf.
Context Between the two scenes Pharisees ask him for a sign from heaven, and he sighs deeply and says none will be given. The disciples' anxiety about bread is answered with arithmetic instead: five loaves, five thousand, twelve baskets; seven loaves, four thousand, seven baskets. He asks the question twice, and the section ends on it unanswered, whether they do not understand yet.
Verses 22-26
Simply A blind man is led out of the village by the hand and healed in two goes. After the first, he can see people but they look like trees walking about; after the second, he sees everything clearly.
Verses 27-33
Simply On the road he asks what people are saying about him, and then asks the disciples directly. Peter answers that he is the Christ, and is told to say nothing to anyone.
Context Then he says openly what that will mean: the Son of Man must suffer, be rejected by the elders and chief priests and scribes, be killed, and rise after three days. Peter takes him aside to rebuke him for it, and is rebuked back in the hardest words in the gospel, that he is thinking the things of men and not the things of God. Right answer, wrong picture, in the space of four verses.
Verses 34-38
Simply He calls the crowd over, not just the disciples, and says the same road is theirs: deny yourself, take up your cross, follow. Whoever tries to save his life will lose it, and whoever loses it for his sake will save it.
Context The two questions that close the chapter are put in the language of trade, what a man gains and what he could give in exchange, and the thing being weighed is his own life. The cross is named here for the first time in this gospel, and the first person told to carry one is whoever happens to be listening.